1. Field of the Invention
The present invention relates to a method of and to an apparatus for producing a vertical or inclined drill hole in a mine, a deposit or the like, by full profile drilling which takes place upwardly and from a roadway, a starting chamber or the like utilizing a rotatable and advancable drilling tool and a train of drilling rods leading to this drilling tool.
2. Description of the Prior Art
It is frequently found to be desirable or necessary to drill from a starting chamber, upwardly into solid material, e.g. because local conditions or requirements imposed by the operating procedures do not permit a drill hole to be produced downwardly or do not permit a pilot hole, passing to the target area, to be initially formed (this pilot hole being susceptible of widening later). However, the upward formation of a full drilling is accompanied by considerable difficulties and presents problems both in respect of the working procedures employed and also in respect of the drilling equipment used.
It is known to provide, at the upper end of a nonrotating train of drilling rods, a drilling head with which an electrical rotary drive is directly associated. Because this driving motor functions in the drilling hole and moves with the drilling head, an electrical energy supply line must be provided which leads from the starting chamber and passes, through the drill hole, to the drilling head. This means that sensitive parts, which are of high value, lie, with the drive motor and its supply means, in the drill hole. If a drill hole has to be abandoned due to breakage of the drilling rod train, a mine cave in, or due to other influences, not only will the drilling head be lost, but with it the valuable driving means. In the case of an apparatus of this kind the feed movement is produced in the starting chamber and must be transmitted to the drilling head through the train of drilling rods. Accordingly, the drilling rod train is loaded by the whole feeding force and in this way is subject to a high degree of buckling stress. This means that a heavy drilling rod train is needed, and also a relatively large number of stabilizers have to be used.
It is also known to produce both the feed for advancing movement and the torque for the drilling head in the starting chamber. A raisable rotary table is provided for this purpose. Both movements must then be transmitted to the drilling head by means of the train of drilling rods. The train of drilling rods is, accordingly, not only subject to buckling stress but also to rotary stress. By reason of the combination of rotation with simultaneous compressional stress alternating bending stresses are experienced.